Aluminum crimp closures provide a secure leak-resistant seal Aluminum seals must be applied with a crimping tool Shop Fisherbrand™ 11mm Aluminum Crimp Seal, Silver, Fisherbrand™ 11mm Aluminum Crimp Seal, Silver, Center Hole, Assembled Septum: Autosampler Vial Caps and Closures Autosampler Vials, Caps, and Closures | Fisher Scientific